Two-piece buckles comprise releasably connectable male and female members. The buckles are typically used to fasten the ends of belts or straps, wherein each of the male and female members is attached to one end of the belt or strap. The buckles have various applications, but are particularly common in sports and camping equipment like backpacks and life jackets.
The male member of the buckle typically includes a pair of resilient arms that may be inserted and releasably locked in the female member to couple the members. Each arm includes an abutment surface that is releasably engageable with a corresponding retaining surface in the female member to lock the members together. Side-release buckles include recesses at the sides of the female member that expose the arms of the male member such that the male and female members may be uncoupled by pressing the arms of the male member at the side recesses to disengage the abutment and retaining surfaces.
U.S. Pat. Nos. 4,577,377; 4,672,725; and 4,987,661 all issued to Kasai, disclose two-piece side-release buckles wherein the female member includes a pair of external actuating members. The actuating members, when pressed, act against the arms of the male member and cause the abutment and retaining surfaces on the male and female members, respectively, to become disengaged. The actuating members are not connected to the male member and can thus extend outwardly from the buckle, making the buckle easier to uncouple by a user wearing gloves or mittens.
One problem with known buckles like those described above is that when large loads are applied to the buckles, the arms of the male member tend to flex inwardly, causing the abutment and retaining surfaces to disengage and leading to an inadvertent separation of the male and female members.
U.S. Pat. No. 5,222,279 issued to Frano and U.K. Patent Publication No. 2,262,962 to Fudaki each disclose buckles comprising a male member having arms, portions of which are engageable with the female member. The engageable portions are noted to be located at positions on the arms such that torque at the arms is reduced to lessen the chance of inadvertent separation. In each reference, however, the arms are designed to perform both engagement and disengagement functions; the arms include portions exposed through side openings in the female member that can be pressed to uncouple the parts. Accordingly, the arms in the male member must De widely spaced-apart and located in close proximity with the sides of the female member. The female member must also include ramps and engagement surfaces proximate its sides engageable by the arms. Therefore, brackets in accordance with these prior art references must be substantially wide in order to accommodate the design of the parts therein and cannot be made suitably compact. Another problem with the buckles disclosed in the prior art references is that it is often difficult to uncouple the male and female parts because the arms of the male member must be directly pressed by the user of the buckle and the engaging portions of the arms must be moved a sufficient distance to disengage the parts. The uncoupling process is especially difficult if the user is wearing gloves or mittens.